#include <iostream>
#include <stdio.h>

using namespace std;

int main(void)
{
	double p, q;
	cin >> p >> q;
	
	p /= 100, q /= 100;
	double ans = p*q / (p*q + (1-q)*(1-p));
	printf("%.11f\n", ans*100);
	
	return 0;
}